We find a sufficient condition to establish that certain abelian groups are not CI-groups with respect to ternary relational structures, and then show that the groups Z3×Z2, Z7×Z2, and Z5 ×Z2 satisfy this condition. Then we completely determine which groups Z2 ×Zp, p a prime, are CI-groups with respect to color binary and ternary relational structures. Finally, we show that Z2 is not a CI-group...